*2.1. Visual Assessment of the Films*

The visual assessment of edible films is necessary to determine the overall quality, appearance, and uniformity of the film structure. This is a crucial aspect for visually assessing hydrogel-based films in terms of their functionality and acceptance by consumers. The visual appearance of the films can impact the consumer perception of the product's quality and visual defects such as tears, pores, poor mechanical strength, and inconsistencies in thickness. The visual appearance of the SA–AG composite edible films loaded with CEO is shown in Figure 1. In general, as the amount of CEO in the film increased, a less transparent appearance of the film was observed in comparison with the control film. The incorporation of oil resulted in a slightly yellow appearance of the films. The control film sample showed good uniformity and was more transparent compared with film samples that were loaded with oil. However, the CEO-loaded films had good flexibility and physical attributes compared with the control. Moreover, different factors can impact the visual characteristics of the films such as the film composition, the preparation technique, handling, and storage conditions.

**Figure 1.** Visual assessment of SA–AG-based composite edible films; AC-1/Control, AC-2 contains 15 μL of CEO, AC-3 contains 20 μL of CEO, and AC-4 contains 30 μL of CEO. **Figure 1.** Visual assessment of SA–AG-based composite edible films; AC-1/Control, AC-2 contains 15 µL of CEO, AC-3 contains 20 µL of CEO, and AC-4 contains 30 µL of CEO.

that were loaded with oil. However, the CEO-loaded films had good flexibility and physical attributes compared with the control. Moreover, different factors can impact the visual characteristics of the films such as the film composition, the preparation technique, han-

#### *2.2. Thickness of the Films 2.2. Thickness of the Films*

dling, and storage conditions.

The thickness of edible films can vary depending on the type of material and the process used for the preparation. The composite hydrogel-based films based on SA and AG were examined for thickness measurement and the results are presented in Table 1. The control (AC-1) showed minimum thickness (0.065mm) compared with the samples loaded with CEO. The incorporation of the CEO in films significantly increased the thickness from 0.065 to 0.11 mm, with the maximum thickness in the AC-4 sample containing the maximum concentration (30 μL) of the CEO, followed by AC-3 and AC-2. The increase in the thickness could be due to the increase in the viscosity of the film-forming solution with the addition of CEO. Zhou et al. [20] also reported similar results, where the thickness of cassava starch-based films increased when the concentration of the CEO increased. Thickness also affects other parameters, such as mechanical and barrier properties, as well as the transparency and visual appearance of the films. Therefore, the thickness of biopolymer-based edible films is an important factor that needs to be carefully controlled during the preparation of the films to achieve optimal properties for their intended application. The thickness of edible films can vary depending on the type of material and the process used for the preparation. The composite hydrogel-based films based on SA and AG were examined for thickness measurement and the results are presented in Table 1. The control (AC-1) showed minimum thickness (0.065mm) compared with the samples loaded with CEO. The incorporation of the CEO in films significantly increased the thickness from 0.065 to 0.11 mm, with the maximum thickness in the AC-4 sample containing the maximum concentration (30 µL) of the CEO, followed by AC-3 and AC-2. The increase in the thickness could be due to the increase in the viscosity of the film-forming solution with the addition of CEO. Zhou et al. [20] also reported similar results, where the thickness of cassava starchbased films increased when the concentration of the CEO increased. Thickness also affects other parameters, such as mechanical and barrier properties, as well as the transparency and visual appearance of the films. Therefore, the thickness of biopolymer-based edible films is an important factor that needs to be carefully controlled during the preparation of the films to achieve optimal properties for their intended application.

**Table 1.** The thickness, tensile strength, elongation at break, moisture content and water vapor permeability of SA–AG hydrogel-based films.


Means carrying the same letters are significantly identical (*p* > 0.05).
